The repository should help resolve printing difficulties with all Samsung (and certain Xerox and Dell) printers. However, not all Samsung printers actually need the Samsung drivers, and the Samsung drivers still contain bugs affecting some printers. Many Samsung printers are now automatically recognized by Debian-based distributions (especially Ubuntu) if connected by USB, and more with each new release of the distributions (generally by Foomatic, as described below). If you just have a basic printer (not multifunction), this will probably work fine, and you can stop reading now unless problems develop.
On the other hand, if you have a multifunction printer, you will almost certainly not be able to access scanning without installing the Samsung driver, either via the repository or manually. Many CLP-, CLX-, and SCX- printers will be missing printing options in some or all of the alternatives below. In general, network printers are still a significant problem for many non-Samsung drivers.
Below is a list of alternatives to this repository that may work for you. I do not advocate any of these solutions (if any of them worked for me, I'd never have created this repository in the first place), but many people have had success with them. All of the solutions below are compatible with having the repository configured, and as described on the v3 information page, the repository is a much better solution than a manual install of the Samsung drivers.
Chances are that it will work fine with CUPS as a generic postscript printer. You may not have all the options available for your printer, though. Many ML- line of printers will work with this approach. A variation on this approach is to download the Samsung Unified Linux Driver and only pull out the ppd file for your printer, install it to CUPS, and hope for the best; much of the time this won't work, but it may enable duplexing or other more advanced features. See here for an example of how to do this.
CUPS and the SpliX Driver
For a subset of Samsung (and Xerox and Dell) printers, the SpliX driver v2.0 (available in the Ubuntu and Debian repositories) may provide essentially complete printing capabilities. You can find a list of supported printers at the SpliX website. Some people have had excellent success with this driver. I have not had as much luck, in part because of bugs in ghostscript, which SpliX uses to print. In addition, SpliX seems to be more reliable and provide auto-detection when connected by USB; network connections may not work as well. There is also a SpliX repository.
Foomatic
Foomatic (installed by default in Ubuntu and Debian) has default support for most of the ML- and CLP- printers, as well as a few of the CLX- and other models, but little or no support for SCX- models. This is what your computer is usually doing when your system automatically recognizes and configures your USB printer on an Ubuntu system. In some cases, the printer driver that is automatically selected by Foomatic/CUPS may not work, and you may still want to try manually configuring the printer with a different CUPS or Foomatic driver using the standard interface(s). In the most recent versions of Ubuntu (10.04 and later), the software may assume you are stupid and keep overriding your choice of driver with the default Foomatic one (whether or not that driver actually works). In this case, try installing the driver through the Samsung Configurator interface and/or removing Foomatic.
In addition, there is the related foo2qpdl driver that supposedly greatly improves performance with certain CLP- and related printers; however, use this as your own risk, as I have never tried it and it is not officially supported by Debian or Ubuntu. For reasons that have nothing to do with my printer, I have never really cared for Foomatic, and so haven't personally tried this approach. However, default Foomatic (not requiring the foo2qpdl driver) should work for many users. Only certain multifunction printers will have scanning enabled using this approach.
Mixed Repository and Default (Usually Foomatic) Driver
If you have a multifunction printer that works fine as a printer using default drivers (CUPS and/or Foomatic), but would like scanning functions, this approach may work. Set up the repository as described on the main page, and install the samsungmfp-scanner package. This package will also bring in all the necessary driver files. At this point, you can either reconfigure your printer to use the Samsung Unified Linux Driver (by adding a new printer using the Samsung ppd files via the CUPS printer administration tool), or leave the printer component as-is and only make use of the Samsung driver for scanning. The samsungmfp-scanner package should enable scanning such that programs (such as xsane) will recognize the scanner of a multifunction printer connected by USB.
Other Solutions
Additional information for specific printers may also be available at linuxprinting.org.